Apparatus for sequentially compressing resilient articles



March 17, 1964 R. 1... SURINA 3,125,020

APPARATUS FOR SEQUENTIALLY COMPRESSING RESILIENT ARTICLES 5 Sheet'sSheet1 Filed April 9, 1962 lNVENTOR P. L. sUQiN A March 17, 1964 su APPARATUSFOR SEQUENTIALLY COMPRESSING RESILIENT ARTICLES \NVENTOE E.L.SUEINAATTORNEY 5 Sheets-Sheet 2 Filed April 9, 1962 March 17, 1964 R. SURINAAPPARATUS FOR SEQUENTIALLY COMPRESSING RESILIENT ARTICLES Filed April 9,1962 5 Sheets-Sheet 5 6 mvemoe E. L. SUEWA BY C9 5 ATTORNEY March 17,1964 R. L. SURINA APPARATUS FOR SEQUENTIALLY COMPRESSING RESILIENTARTICLES 5 Sheets-Sheet 4 Filed April 9, 1962 INVENTOE E. L. SUQlNA BY J%TTOENEY United States Patent 3,125,020 APPARATUS FOR SEQUENTIALLYCOR/RRESSING RESILIENT ARTICLES Robert L. Sarina, Westmont, IlL,assignor to Western Electric Company, Incorporated, New York, N.Y., acorporation of New York Filed Apr. 9, 1962, Ser. No. 186,031 8 Claims.(Cl. 100-415) The present invention relates generally to apparatus forsequentially compressing resilient articles, and more particularly toapparatus for loading and compressing resilient articles in a rack bystages. Accordingly, the general objects of the invention are to providenew and improved apparatus of such character.

It is often required that resilient articles be compressed to somethickness less than the original thickness. In the past, this has beenaccomplished by compressing each article individually or inserting alarge quantity of such articles into a container and compressing them inmass, all at once. Both procedures have their shortcomings, for tocompress each article individually is time consuming and inefficient.Yet, to compress them in mass results in a nonuniform distribution ofthe pressure exerted to compress the articles and consequentlynonuniform compressed thicknesses of the articles.

Accordingly, other objects of the invention are to provide new andimproved apparatus for loading and compressing resilient articles in arack by stages, wherein the articles are alternately inserted andcompressed in groups several articles thick so that the pressure exertedto compress the articles is uniformly distributed, resulting in uni formcompressed thicknesses of the articles.

In the specific field of manufacturing certain capacitors, a wide sheetof metallized Mylar is wound into a long cylindrical capacitor roll,where the Mylar serves as a dielectric between adjacent metal layers.These rolls are cut into several capacitor bodies of a desired lengthwhich must be compressed with spacer plates at a particular pressure toform spacer-separated flat capacitor bodies and loaded into Ll-shapedracks so that the capacitor bodies are aligned in columns and layerswith their ends exposed for subsequent solder-capping and lead-attachingoperations. It is requisite that the pressure exerted to compress thecapacitor bodies be uniformly distributed so that all of the capacitorsare compressed to the same thickness.

Therefore, further objects of the invention are to provide new andimproved apparatus for loading and compressing spacer-separatedresilient capacitor bodies in a rack by stages so that the pressureexerted to compress the capacitor bodies is uniformly distributed to allof them and further, so that the capacitor bodies are inserted in therack in layers and in columns which are uniformly aligned.

With the foregoing and other objects in mind, apparatus in accordancewith certain aspects of the invention includes a holder defining achamber into which articles are inserted in groups which are severalarticles thick. Each succeeding group, after the first, is insertedagainst the outer surface of the preceding group after the precedinggroup has been compressed. A reciprocable mechanism is provided forcompressing each group in turn to a lesser thickness, the first groupbeing compressed against a base surface of the chamber and thesucceeding groups respectively against the outer surfce of the precedingcompressed group. Mechanism is provided for engaging and holding theouter surface of each compressed group after the compression operationand before the retraction of the compressing mechanism to maintain thecompressed state of the previously. compressed articles.

According to certain more specific aspects of the in- 3,125,020 PatentedMar. 17, 1964 "ice vention, the engaging and holding mechanism includesa plurality of fingers spaced to engage and hold the outer surface ofthe compressed groups. A mechanism is provided for moving the fingersinto and out of the chamher and lengthwise thereof so that they aremoved into engagement with the outer surface of each compressed group inturn. In addition, the holder constitutes a I..l-sl1aped rack, and arectangular frame is provided for holding the rack vertically erect. Amechanism having a plurality of equally spaced fingers is provided fordefining openings into which articles are inserted to form a layer inthe rack so that the articles of successive layers are uniformly alignedin columns. This function is facilitated by mounting the fingeredmechanism on the upright frame for vertical movement relative theretoand for horizontal movement into and out of the rack.

Other objects, advantages, and aspects of the invention will appear fromthe following detailed description of a specific embodiment thereof,when taken in conjunction with the appended drawings, in which:

FIG. 1 is a perspective view of an apparatus forming a preferredembodiment of the invention;

FIG. 2 is a front view of the apparatus with several articles insertedin layers in the rack;

FIG. 3 is an enlarged sectional view taken generally along the line 3-3in FIG. 2, specifically showing the tray and the engaging and holdingmechanism;

FIG. 4 is a sectional view of the tray taken generally along the line 44in FIG. 3;

FIG. 5 is a sectional View of the engaging and holding mechanism takengenerally along the line 55 in FIG. 3;

FIG. 6 is a sectional drawing of the engaging and holding mechanismshown in FIG. 5, but with the fingers and the pawl in a retractedposition; and

FIG. 7 is a schematic diagram of the control circuit for actuating thepneumatic cylinder.

Referring now in detail to the drawings and particularly to FIGS. 1 and2, an apparatus in accordance with a preferred embodiment of theinvention is utilized to load and compress capacitor bodies inspacer-separated layers by stages. Generally, the spacer-separatedlayers of capacitor bodies, including the spacers, constitute theresilient articles to be compressed and typify the use of the invention;however, various dilferent types of articles, composite or uniform, maybe compressed equally well using the apparatus of the invention. Theapparatus includes a rectangular frame 10 defining an opening 11 intowhich a L! -shaped rack 12 is inserted, the bottom thereof beingchanneled to receive a pair of stops 1313 mounted on a base plate 14 ofthe frame 1th. The rack 12 is secured in the frame 14 by a pair ofclamps 1515 which are lowered so that they overlie the upper edges ofthe rack 12. Capacitor bodies 16--16 to be inserted into the rack 12 areplaced in mass into a tray 17 so that an operator can insert them intothe rack to form a layer with simple and efiicient hand-movements of alimited distance each.

To aid in this function, the tray 17 is mounted from the front of theframe 16 for vertical movement on a pair of fixed guide rods 1818slidably received in associated bushings 119 on the tray 17, as shown inFIGS. 3 and 4. In addition, a slide 21 is mounted beneath the tray 17 ina pair of guides 2222, as shown in FIGS. 2 and 4, for horizontalmovement into and out of the rack 12, the slide 21 having equally spacedfingers 2323 defining openings 2424 into which the capacitor bodies 116are inserted when the slide is advanced to the position shown in FIGS. 3and 4. All of the above-mentioned movements of the tray 17 and the slide21, both dependent and independent, are accomplished by elevating orlowering and pushing or pulling a handle 26 depending from the slide.

Initially, the operator" positions the tray 17 near the bottom of theframe 10 and advances the fingers 23-23 of the slide 21 with the handle26 so that the fingers 23- 23 overlie and rest on a thick spacer plate27 (FIG. 2) inserted at the bottom of the rack 12. Capacitor bodies16-16 from the tray 17 are then inserted between the fingers 23-2-3 toform a layer in the rack and a thin spacer plate 28 is placed on top ofthe layer. The tray 17 is subsequently repositioned at the proper heightfor the succeeding layers by (l) withdrawing the slide 21 from withinthe rack 12, (2) elevating the tray 17 to a position above the layerjust inserted, (3) advancing the slide into the rack again so that thefingers 23-23 overlie the spacer plate 28, and (4) lowering the tray sothat the fingers rest on the spacer plate. Capacitor bodies 16-16 arethen inserted between the fingers 23-23 again and the operation repeateduntil a selected number of layers separated by thin spacer plates 28-28have been inserted into the rack 12.

When the selected number of layers, as for example fifteen, has beeninserted in the rack 12, a thick spacer plate 27 is placed on top of thepile-up of layers and a pneumatic cylinder 29 is actuated to extend aram 31 so as to engage the thick spacer plate 27 and compress thepile-up of layers therebeneath against the bottom spacer plate 27 undera predetermined amount of pressure. The selection of the number oflayers to be compressed at one time is not arbitrary, for the numbermust be great enough to insure a high degree of efficiency, but not sogreat as to preclude uniform pressure distribution among the capacitorbodies 16-16 in any one particular layer and also among each of thevarious layers. In this particular example, fifteen layers is theselected number because this is the optimum number of layers that can becompressed at one time and still result in uniform distribution of thepressure among the various layers. In addition, the thick spacer plate27 is provided in this specific example to insure that the pressure willbe uniformly distributed among all of the capacitors in any one layer.

After a pile-up of fifteen such layers has been compressed, a carriage32 mounted at the rear of the frame 10 (FIGS. 1, 3, and 6) is lowered ona pair of guide rods 33-33 slidably received in a pair of bushings 34-34 so that a pair of fingers 36-36 can be inserted through verticallyelongated slots 37-37 in a back plate 37 to a position within the rack12 where they overlie the con1- pressed pile-up. The insertion of thefingers 36-36 is initiated by a pair of handles 38-38 pivotably mountedto the carriage by pins 33-39 so that they extend toward the front ofthe frame 16, one from either side thereof.

Movement of the handles 38-38 from the position shown in FIG. 3 in thedirection indicated by the arrows X-X is transmitted through pins 41-41,slidably received in grooves 42-42 of the handles, to a slide 43,causing it to move forward relative to the carriage 32 in the directionindicated by the arrow Y. The fingers 36- 36 are mounted at the forwardedge of the slide 43 and are of such length that they overlie thecompressed pileup, as illustrated in FIG. 5, when the handles 38-38 havebeen actuated to move the slide 43 forward.

This same movement is transmitted to a pawl 44, slidably mounted on thecarriage 32, through a lost-motion coupling 46 to engage the pawl 44with the teeth 47 on a toothed rack 43 vertically disposed at the rearof the back plate 37' as shown in FIG. 5. The lost-motion coupling 46includes a pin 49 projecting downward from the pawl 44, which pin 49 isslidably received first through a slot 52 in a portion 53 of thecarriage 32 separating the pawl 44 from the slide 43, and then in a slot54 in the slide 43. calculated to limit the movement of the pin 49 tojust that amount necessary to engage and disengage the pawl 44 with theteeth 47-47 of the rack 43. On the other hand, the second slot 54 is ofsuch length as to allow the The length of the first slot 52 is 4 slide43 to fully withdraw the fingers 36-36 from over the pile-up before thefront edge of the slot 54 engages the pin 49 to disengage the pawl 44from the rack 48 (FIG. 6), the pin 49 being constantly biased toward thefront edge of the first slot 52 by a spring 56.

Thus, by spreading the handles 38-38 apart, the slide 43 is movedforward (1) to extend the fingers 36-36 so that they overlie the pile-upand (2) to move the pawl 44 into engagement with the rack 48 to lock thecarriage 32 against elevational movement by permitting the spring 56 tobias the pin 49 against the front edge of the first slot 52 (FIG. 5).With the fingers 36-36 so extended, the rear edge of the second slot 54does not engage the pin 49, but instead is coextensive with the rearedge of the first slot 52 so that the pawl 44 is free to ratchet overthe teeth 47-47 of the rack 48 against the bias of the spring 56 whenthe carriage 32 is lowered to engage and hold down the compressedpile-up with the fingers 36-36.

The pneumatic cylinder 29 is then actuated to retract the ram 31 so thatanother group of fifteen layers of uncompressed capacitor bodies 16-16may be inserted into the rack 12, after which the pneumatic cylinder 29is again actuated to compress the newly inserted layers against thethick spacer plate 27 on the upper layer of the pile-up held in acompressed state by the fingers 36- 36. With the newly inserted layersso compressed, the handles 38-38 are pulled forward so as to retract theslide 43 to withdraw the fingers 36-36 from over the pile-up anddisengage the pawl 44 from the rack 48. The carriage 32 is then elevatedby pulling up on the handles 38-38 to a position where the fingers 36-36may again be extended so as to overlie the newly compressed pile-up oflayers, after which the carriage 32 is lowered so that the fingers 36-36engage and hold down the upper layer of the compressed pile-up, the pawl44 locking the carriage 32 against elevational movement as before.

These operations of alternately loading and then compressing capacitorbodies 16-16 in the rack 12 by stages are continued until the rack hasbeen filled to capacity, at which time it is capped and removed from theframe 10 for subsequent operations. If for some reason it is desired tosuspend the tray 17 in a position above the normal rest position on topof the uppermost layer of capacitor bodies 16-16, a locking mechanism 57is provided for just that purpose. The locking mechanism 57 includes alever 58 pivotally mounted at the right side of the tray 17, as viewedin FIGS. 1 and 2, which is provided with an oversize bore 59 throughwhich one of the guide rods 18 passes so that the peripheral edges ofthe bore 59 engage and hold fast to the guide rod 18 when the lever 58is pivoted downward at its remote end 61. The locking mechanism 57 isreleased again by raising the remote end 61 of the lever 58 to disengagethe peripheral edges of the bore 59.

Operation After a Ll-shaped rack 12 has been inserted and clamped Withinthe rectangular frame 10, the operation of this device is commenced byfirst lowering the tray 17, filled with capacitor bodies 16-16, andinserting the fingers 23-23 into the rack 12 so that they overlie andrest on a thick spacer plate 27 inserted at the bottom thereof.Capacitor bodies 16-16 are then inserted in the openings 24-24 definedby the fingers 23-23 to form a layer and a thin spacer plate 28 isplaced on top of the layer. The tray 17 is subsequently repositioned atthe proper height for the succeeding layer by (1) withdrawing the slide21 from within the rack 12, (2) elevating the tray 17 to a positionabove the layer just inserted, (3) advancing the slide into the rackagain so that the fingers 23-23 overlie the spacer plate 28, and (4)lowering the tray so that the fingers rest on the spacer plate 28.Capacitor bodies 16-16 are then inserted between the fingers 23-23again, and the operation repeated until fifteen such layers separated bythin spacer plates 2828 have been inserted into the rack 12.

After fifteen such layers have been inserted, a thick spacer plate 27 isplaced on top of the pile-up and the operator presses two push-buttonswitches 62 and 63, one with each hand, to actuate the pneumaticcylinder 29 to compress the pile-up. The requirement that the operatorpress both push-button switches 62 and 63 is provided as a built-insafety feature, and he must hold these buttons down until the ram 31exerts a predetermined amount of pressure in compressing the pile-up oflayers as an additional safety measure.

These safety features are incorporated as part of the electrical circuitshown in FIG. 7 for actuating the pneumatic cylinder 29. Before thepush-button switches 62 and 63 are pressed, the switches complete acircuit to a first control relay 64 which locks itself in an energizedstate by closing a contact 66 to by-pass the switches 62 and 63. Whenthe two push-button switches 62 and 63 are pressed, normally opencontacts 67 and 68 respectively associated therewith are closed (theenergization of the relay 64 having already closed a contact 69) tocomplete a circuit to a solenoid valve 71. The operator must hold theswitches 62 and 63 down to maintain the completed circuit to thesolenoid valve 71 until the ram 31 exerts a predetermined amount ofpressure on the pile-up, at which time a pressure-sensitive diaphragm 72closes a switch 73 to complete a circuit (in combination with a contact74 which was also closed by the energization of the control relay 64) toa second control relay 76. Energization of the second control relay 76closes a locking contact 77 and a contact 78, the closing of the latterenabling the operator to discontinue holding down the switches 62 and 63without causing an open circuit to the solenoid '71 since the contact 78parallels the switch contacts 67 and 68.

With the ram 31 still extended and holding the pile-up in a compressedstate, the fingers 36-36 are extended to overlie the pile-up and thepawl 44 is engaged with the toothed rack 48, after which the carriage 32is lowered until the fingers 36-36 engage the thick spacer plate 27, thepawl 44 locking the carriage 32 against elevational movement to hold thepile-up in a compressed state. The ram 31 is retracted in the pneumaticcylinder 29 by pressing a push-button switch 79 to open a normallyclosed contact 61, thereby deenergizing the solenoid valve 71 andenabling a spring (not shown) to reverse the solenoid valve 71. Thepressingof the pushbutton switch 79 also deenergizes the control relays64 and 76 and thereby causes the contacts associated therewith to returnto their initial positions.

The tray 17 is then repositioned and the fingers 23-23 extended for theinsertion of the next layer of capacitor bodies 16-16 on top of thethick spacer plate 27. The capacitor-body inserting operations are thenrepeated until another group of fifteen layers has been inserted and thepneumatic cylinder 29 is again actuated to compress the newly insertedlayers against the upper layer of the previously compressed pile-up.With the newly inserted layer so compressed, the fingers 36-36 arewithdrawn from the pile-up and the pawl 44 is disengaged from the rack48 by the handles 38--38. The carriage 32 is then elevated to a positionabove the newly compressed pile-up where the fingers 36-36 are againextended and the pawl 44 engaged, after which the carriage 32 is loweredto engage and hold down the upper layer of the composite, compressedpile-up.

These operations of alternately loading and then compressing capacitorbodies l6-16 in the Ll-shaped rack 12 by stages is continued until therack has been filled to capacity, at which time it is capped and removedfrom the frame 16 for subsequent operations.

While one specific embodiment of the invention has been described indetail hereinabove, it will be obvious 6 that various modifications maybe made without departing from the spirit and scope of the invention.

What is claimed is:

1. Apparatus for sequentially compressing resilient articles, whichcomprises:

a holder defining a chamber into which the articles to be compressed maybe inserted in a succession of loosely stacked groups with eachsucceeding group after the first being placed against an outer surfaceof the preceding group after the preceding group has been compressed;

reciprocable means for compressing each group of articles in turn to alesser thickness, the first group being compressed against a basesurface of the chamber, and the succeeding groups respectively againstthe outer surface of the preceding group;

means for engaging and holding the outer surface of the compressed groupafter each compression operation to maintain the compressed state of thepreviously compressed articles; and

means for moving said engaging and holding means into and out of thechamber and along said holder, so that said engaging and holding meansmay be moved into engagement with the outer surface of each compressedgroup in turn after the compression operation and before the retractionof said compressing means.

2. Apparatus for sequentially compressing resilient articles, whichcomprises:

a holder defining a chamber into which the articles to be compressed maybe inserted in a succession of loosely stacked groups which are severalarticles thick with each succeeding group after the first being placedagainst the outer surface of the preceding group after the precedinggroup has been compressed;

reciprocable means for compressing each group of articles in turn to alesser thickness, the first group being compressed against a basesurface of the chamher, and the succeeding groups respectively againstthe outer surface of the preceding group;

a plurality of fingers spaced to engage and to hold the outer surface ofeach compressed group in turn after the compression operation and beforethe retraction of said compressing means, to maintain the compressedstate of the previously compressed articles; and

means for moving said fingers into and out of the chamber and along saidholder, so that said fingers may be moved into engagement with the outersurface of each compressed group in turn regardless of the total numberof compressed groups, the chamber being slotted to permit the recitedmovements of said fingers.

3. Apparatus for loading and compressing resilient articles in a rack bystages, which comprises:

a frame for receiving and holding the rack so that articles may beinserted therein in groups of loosely stacked layers with each groupsucceeding the first being placed against the outer layer of thepreceding group after the preceding group has been compressed;

reciprocable means for compressing each group in turn to a lesserthickness, the first group being compressed against the base surface ofthe rack and the succeeding groups respectively against the outer layerof the preceding group;

means for engaging and holding the outer layer of the compressed groupafter each compression operation to maintain the compressed state of thepreviously compressed articles; and

means for moving said engaging and holding means into and out of therack and lengthwise of said frame, so that said engaging and holdingmeans may be moved into engagement with the outer layer of eachcompressed group in turn after the compression oparticles in a ,U-shaped rack by stages, which comprises:

an upright, rectangular frame for receiving and holding the rackvertically erect with the open sides thereof exposed so that articlesmay be inserted therein in groups of spacer-separated layers with eachgroup succeeding the first being placed on top of the preceding groupafter the preceding group has been compressed;

reciprocable means for compressing each group in turn to a lesserthickness, the first group being compressed against the bottom of therack and the succeeding groups respectively against the uppermost layerof the preceding group;

means for engaging and holding down the uppermost layer of thecompressed pile-up after each compressing operation to maintain thecompressed state of the previously compressed articles; and

means for moving said engaging and holding means into and out of therack and vertically along said frame, so that said engaging and holdingmeans may be moved into engagement with the uppermost layer of thepile-up after each compressing operation to hold the pile-up in thecompressed state while (1) said compressing means is retracted, (2) anew group of uncompressed layers is inserted, and (3) said compressingmeans is again actuated to compress the newly inserted uncompressedgroup.

5. The apparatus as recited in claim 4, wherein the engaging and holdingmeans comprises:

a carriage slidably mounted on the upright frame for vertical movement;and

extendable fingers slidably mounted horizontally on said carriage suchthat they overlie the pile-up of layers, through an open side of theLil-shaped rack, in an extended position, but not in a retractedposition, said carriage being so positionable with said fingers extendedthat said fingers engage and hold down the uppermost layer of eachsucceeding group in turn after it has been compressed; and

wherein the moving means for the holding and engaging means includes:releasable means for locking said carriage against elevational movementrelative to the frame when said fingers overlie and are engaged with theuppermost layer of the compressed pile-up so that the pile-up is held inthe compressed state, said locking means being released after a newgroup has been inserted and compressed to facilitate adjustment of saidfingers and said carriage to hold down the uppermost layer of the newlycompressed group.

6. The apparatus as recited in claim 4, wherein the a carriage mountedon the upright frame for vertical sliding movement;

a spring-biased pawl slidably mounted on said carriage for releasableengagement with the teeth on said toothed rack, said pawl locking saidcarriage against elevational movement when engaged with said toothedrack;

extendable fingers slidably mounted horizontally on said carriage suchthat they overlie the pile-up of layers through an open side of theLl-shaped rack, in an extended position, but not in a retractedposition; and

reciprocable means for simultaneously extending said fingers andengaging said pawl with said toothed rack so that said fingers engageand hold down the uppermost layer of the compressed pile-up, and forsimultaneously retracting said fingers and disengaging said pawl, aftera new group has been inserted and compressed, so that said carriage canbe elevated to a position where said fingers can be extended and saidpawl engaged to hold down the new uppermost layer of the compressedpile-up.

7. The apparatus as recited in claim 4, wherein:

means are provided, including a plurality of equally spacedfingers, fordefining openings into which articles are inserted to form a layer inthe rack so that the articles of successive layers are uniformly alignedin columns; and

means are provided for mounting said fingered means on the upright framefor vertical movement relative thereto and for horizontal movement intoand out of the rack.

8. The apparatus as recited in claim 4, wherein:

a tray is slidably mounted on said upright frame for vertical movement,said tray being designed to hold articles to be inserted in the U-shapedrack so that they are readily accessible for such insertion; and

a slide having a plurality of equally spaced fingers is mounted fromsaid tray so that the fingers thereon can be extended into and retractedfrom the U -shaped rack through an open side thereof, the fingers beingspaced apart such that articles can be inserted therebetween to form alayer when extended into the rack, said tray initially being positionedwith the fingers extended and resting on the bottom of the rack for theinsertion of the first layer, and is repositioned at the proper heightfor subsequent layers by (1) withdrawing the fingers, (2) elevating saidtray, (3) extending the fingers again, and (4) lowering said tray sothat the fingers rest on the layer just inserted.

References Cited in the file of this patent UNITED STATES PATENTSPortner Jan. 24, 1888 Reeder Mar. 13, 1888 Lowry Mar. 20, 1900 RiedyJuly 12, 1921 Edwards Apr. 8, 1947 Russell Dec. 1, 1953 Eger June 25,1957

1. APPARATUS FOR SEQUENTIALLY COMPRESSING RESILIENT ARTICLES, WHICHCOMPRISES: A HOLDER DEFINING A CHAMBER INTO WHICH THE ARTICLES TO BECOMPRESSED MAY BE INSERTED IN A SUCCESSION OF LOOSELY STACKED GROUPSWITH EACH SUCCEEDING GROUP AFTER THE FIRST BEING PLACED AGAINST AN OUTERSURFACE OF THE PRECEDING GROUP AFTER THE PRECEDING GROUP HAS BEENCOMPRESSED; RECIPROCABLE MEANS FOR COMPRESSING EACH GROUP OF ARTICLES INTURN TO A LESSER THICKNESS, THE FIRST GROUP BEING COMPRESSED AGAINST ABASE SURFACE OF THE CHAMBER, AND THE SUCCEEDING GROUPS RESPECTIVELYAGAINST THE OUTER SURFACE OF THE PRECEDING GROUP; MEANS FOR ENGAGING ANDHOLDING THE OUTER SURFACE OF THE COMPRESSED GROUP AFTER EACH COMPRESSIONOPERATION TO MAINTAIN THE COMPRESSED STATE OF THE PREVIOUSLY COMPRESSEDARTICLES; AND MEANS FOR MOVING SAID ENGAGING AND HOLDING MEANS INTO ANDOUT OF THE CHAMBER AND ALONG SAID HOLDER, SO THAT SAID ENGAGING ANDHOLDING MEANS MAY BE MOVED INTO ENGAGEMENT WITH THE OUTER SURFACE OFEACH COMPRESSED GROUP IN TURN AFTER THE COMPRESSION OPERATION AND BEFORETHE RETRACTION OF SAID COMPRESSING MEANS.